Automatic transmission apparatus has been hitherto known. In one such type of apparatus, a machine casing is provided on one side with an input shaft connected to an internal combustion engine and with a torque convertor connected to the input shaft. The apparatus is further provided in the interior thereof with an output shaft in parallel with the input shaft. The input shaft and the output shaft are interconnected through a high-speed transmission system having a high-speed clutch and a low-speed transmission system having a low-speed clutch.
In this type of apparatus, however, it has been usual for the input shaft to be of the type that the same extends into the machine casing through a direct coupling clutch. Accordingly, this conventional apparatus is subject to the inconvenience that the direct coupling clutch and the torque convertor are disposed on one side of the machine casing so as to be adjacent to one another, and it cannot be avoided that this portion becomes comparatively complicated in construction.